Key terms

ACETYLCHOLINE: A chemical that transmits nerve impulses from one nerve fiber to another (neurotransmitter). The pleasurable effects of nicotine are a direct result of nicotine binding to acetylcholine receptors.CARBON MONOXIDE (CO): A gaseous byproduct of incomplete burning of tobacco. It replaces necessary oxygen being carried by the hemoglobin in the blood and is thought to contribute to the development of cardiovascular disease.CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD): A general term to describe airflow obstruction due to emphysema and chronic bronchitis.COMPENSATORY SMOKING: Smokers puff harder, deeper, and more frequently to obtain desired amounts of nicotine from fewer cigarettes or from low-nicotine cigarettes. Smokers may also hold the smoke in the lungs longer before exhaling and smoke the cigarette further down.COTININE: A breakdown product of nicotine that stays much longer in the blood than nicotine, and so can be used as a measurement of nicotine exposure, ETS exposure, or even nonsmoking compliance.DOPAMINE: Neurotransmitter associated with the regulation of movement, emotional response, pleasure, and pain.EMPHYSEMA: An irreversible, smoking-related disease in which damage of the tiny air sacs (alveoli) in the lung results in air being trapped and a reduced exchange of gases. The result is shortness of breath, wheezing, coughing, and difficulty breathing.ENVIRONMENTAL TOBACCO SMOKE (ETS): Also called passive or second hand smoke, ETS is the combination of the smoke arising from smoldering tobacco together with exhaled smoke and is responsible for extensive health problems in smokers and nonsmokers alike.HALF-LIFE: The amount of time it takes for one half of a substance to be broken down or excreted. Nicotine has a short half-life, therefore, frequent tobacco intake is required to maintain desired nicotine levels in the blood.MASTER SETTLEMENT AGREEMENT (MSA): A 1998 agreement between the States’ Attorneys General and the tobacco industry. Tobacco companies agreed to several changes in advertising and promotion in exchange for protection from further lawsuits. Companies also agreed to pay billions of dollars over 25 years to reimburse states for the cost of treating smoking-related illnesses.NICOTINE: An alkaloid derived from the tobacco plant that is responsible for smoking’s addictive effects; it is toxic at high doses but can be effective as a medicine at lower doses.SMOKER’S COUGH: Recurring cough experienced by smokers because damaged tiny hair-like structures (cilia) in airways can not move mucus and debris up and out efficiently.TAR/TPM: Total particulate matter. An all-purpose term for particle-phase constituents of tobacco smoke, many of which are carcinogenic (cancer-causing) or otherwise toxic.WITHDRAWAL: A group of symptoms that may occur from suddenly stopping the use of a substance such as alcohol or other drugs after chronic or prolonged ingestion.

Overview

Nicotine dependence is almost invariably caused by addiction to tobacco, because tobacco is the overwhelming source of nicotine. Nicotine present within tobacco products causes physical and Mental effects rapidly leading to addiction, and the user continues using tobacco despite adverse health consequences and usually a desire to stop. The widespread use of tobacco, despite its known dangers, probably reflects its low cost and easy availability, its high level of social acceptance until recent years, and its seemingly mild immediate side effects. Nicotine use often begins in adolescence in response to commercial and social pressures and continues because of the positively reinforcing effects of nicotine, which can include both relaxation and increased alertness. In later stages of use, smoking may be used mainly to relieve withdrawal symptoms such as irritability and discomfort.Addictive characteristics of nicotine Nicotine meets the criteria for causing chemical dependence with the following characteristics: • Users can exhibit tolerance, which is when additional amounts of nicotine are required to produce an effect. • A great deal of time may be spent using nicotine (such as leaving work for cigarette breaks), and it is usually taken in larger amounts or over longer periods of time than was intended. • Users may have a persistent desire for nicotine (craving) and unsuccessful attempts to cut down or control its use. • Nicotine causes withdrawal symptoms, and its ingestion may continue despite knowledge of the harm it causes. • Daily tobacco use becomes compulsive, repetitive, and imperative. • The user avoids withdrawal symptoms and experiences the rewards by repeated dosing, that is, by ingesting more nicotine from tobacco products. • There is a high rate of relapse once use ceases. Nicotine dependence resembles that of alcohol, heroin, and cocaine but appears to be more harmless to smokers for two reasons. First, there are usually several years or decades before signs of disease are detected. Second, smoking does not produce a disabling state of intoxication seen with the other drugs. On the contrary, nicotine may improve attention or decrease fatigue and therefore improve performance.Increased risk of developing dependence Risk of dependence and disease increases with the number of cigarettes smoked and duration of smoking. There is a marked increase in dependence when use exceeds five cigarettes daily. The earlier individuals start to smoke, the more severe their addiction will be. People with anxiety and depression are at greater risk of dependence as nicotine is used as a “self-medication” to enhance mood. Youths with adjustment problems, who are risk takers, or have extraverted (outgoing) personalities are at increased risk for smoking. Children whose parents are regular smokers are at high risk. Genetic factors influence the risk of nicotine addiction, as with other addictive substances. Inheriting certain genes can either contribute to or help protect individuals from nicotine addiction. In some cases, the genetic vulnerability to nicotine addiction may be linked to a similar vulnerability to alcohol dependence. Genetic differences in dopamine receptors and rate of nicotine breakdown have been shown to effect the likelihood of nicotine dependence.Introduction into society Ingestion of nicotine is an ancient and widespread practice. Native North, Central, and South Americans have smoked, chewed, sniffed, and drank tobacco preparations for thousands of years. It was used in religious and ceremonial rituals, as a medication, and to suppress hunger. The word tobacco is derived from tobaga pipes used by Central American natives. Christopher Columbus brought the practice back to Europe where it was first used for its medicinal properties. French diplomat Jean Nicot, for whom nicotine is named, helped popularize its use to treat a wide array of illnesses: upset stomachs, ulcers, headaches, toothaches, constipation, and asthma. It was also used as a poultice and antiseptic for cuts, burns, and sores. Nonmedical pipe smoking, chewing, and snuff were initially limited to sailors who had adopted the Native American habit but spread rapidly from Europe to Africa and Asia in the early 16th century. At the same time, there was strong condemnation of tobacco use on both health and social grounds. Popes and kings banned its use, perhaps slowing its spread as its popularity increased. The commercial tobacco industry in North America began in the Jamestown colony in 1612 and grew to be one of the most important national crops over the next 200 years. By the early 1960s pipe smoking and snuff gave way to cigars and cigarettes with the development of a cigarette-rolling machine and the safety match. Cigarette consumption increased during both World Wars, and mass marketing caused a dramatic jump in cigarette use during the next several decades. The height of the smoking epidemic in the United States was in 1965 when 52% of adult men and 32% of adult women smoked. Attitudes of Americans had slowly begun to change by the 1950s when long-term studies clearly linked tobacco and disease. Progress was made nationwide to decrease smoking rates using public health announcements on television, education in schools, increases of federal excise taxes, and warning labels on cigarette packages. In 1971 cigarette advertising was banned from television and radio, and during that same year the nonsmokers’ rights movement began. Social acceptability of smoking began to fall, reinforced by the 1986 Surgeon General’s report focusing on the hazards of environmental tobacco smoke to nonsmokers. By the end of the century, less than 25% of adults smoked, but the rate of decline slowed dramatically in the 1980s and 1990s for both men and women.General impact today Tobacco use, particularly smoking, is the number one cause of preventable death in the United States, causing 20% of all deaths. Smoking is a major risk factor for heart disease, stroke, lung and other forms of cancer, and chronic lung diseases — all leading causes of death. It is a major risk factor for a variety of other medical conditions as well. There are at least 434,000 deaths attributable to smoking per year in the United States, almost 1,200 per day, one every 73 seconds. This death rate is higher than the combined total of deaths due to AIDS, alcohol, cocaine, heroin, homicide, suicide, motor vehicle crashes, and fires. Approximately half of all continuing smokers die from diseases caused by smoking. Of these, approximately half die between the ages 35 and 69, losing an average of 20 to 25 years of life expectancy. Continued smoking throughout life doubles age-specific mortality rates, nearly tripling them in late middle age. Estimates of disease due to smoking do not include the contribution of smoking to overall poor health status. Poor general health may decrease survival for many diseases, including those not caused by smoking, and may limit the treatment options available to the patient. For example, a smoker with emphysema may not be a safe candidate for a surgery needed to treat another medical problem.Reducing tobacco use Despite overwhelming evidence for the adverse health effects of tobacco use, smoking habits have been difficult to change. Nicotine addiction, along with heavy promotion by the tobacco industry, maintains high levels of use. The Centers for Disease Control and Prevention (CDC) estimates that the average 14-year-old has been exposed to more than $20 billion in advertising since age six, creating a “friendly familiarity” with tobacco products. Inl999, total advertising and promotional spending by the tobacco companies rose to $8.24 billion, more than $22 million per day. However, education, combined with community-wide and media-based activities, can postpone or prevent smoking onset in 20% to 40% of adolescents. Studies show that the best ways to reduce tobacco use combine: • restrictions or outright bans on tobacco advertising and promotion • raising excise taxes on tobacco products • enforcement of smoke-free environments in public areas and worksites • banning of tobacco sales in vending machines • warning labels on tobacco products and advertisements • continuous education, especially for minors, on health effects of smoking • a minimum age of 18 for sellers of tobacco products • citation of storeowners who sell tobacco to minors • licensing of tobacco-selling establishments plus compliance checks The FDA was unsuccessful in its attempt from 1995 to 2000 to have nicotine named as a drug and cigarettes named as a drug delivery device and thus subject to FDA control. Such control would have had the potential to severely restrict promotion and access to tobacco products.